Cannabis use for exercise recovery in trained individuals: a survey study.

BACKGROUND: Cannabis use, be it either cannabidiol (CBD) use and/or delta-9-tetrahydrocannabinol (THC) use, shows promise to enhance exercise recovery. The present study aimed to determine if individuals are using CBD and/or THC as a means of recovery from aerobic and/or resistance exercise, as well as additional modalities that might be used to aid in recovery. METHODS: Following consent, 111 participants (Mean ± SD: Age: 31 ± 13 years) completed an anonymous survey. All participants were regularly using cannabis (CBD and/or THC) as well as were currently exercising. Questions pertained to level of cannabis use, methods used for consumption of cannabis, exercise habits, exercise recovery strategies, and demographics. RESULTS: Eighty-five percent of participants reported participating in aerobic training. In addition, 85% of participants also reported regular participation in resistance exercise. Seventy-two percent of participants participated in both aerobic and resistance exercise. Ninety-three percent of participants felt that CBD use assisted them with recovery from exercise, while 87% of participants felt the same regarding THC use. CONCLUSIONS: Individuals who habitually use cannabis, CBD or THC, and regularly engage in exercise do feel that cannabis assists them with exercise recovery. More data are necessary to understand the role of cannabis in exercise recovery as well as perceived ergogenic benefits of cannabis by individuals who both regularly participate in exercise and habitually use cannabis.

The effects of type of recovery in resistance exercise on responses of platelet indices and hemodynamic variables.

To examine the effects of two different volume-matched resistance exercise (RE) recovery protocols (passive and active) on platelet indices and hemodynamic variables. Twelve Healthy participants (mean ± SD; 25 ± 3 yrs) completed a traditional resistance exercise (TRE) protocol that included three sets of six repetitions at 80% one repetition maximum (1RM) with two minutes passive recovery between sets, exercises and an interval resistance exercise (IRE) protocol that included three sets of six repetitions at 60%1RM followed by active recovery including six repetitions of the same exercise at 20%1RM. Blood samples for multiple platelet indices were taken before the protocols, immediately-post (IP), and after 1-hour recovery. Hemodynamic variables were measured before, IP, and every five minutes during recovery. Mean platelet volume and platelet large cell ratio P_LCR decreased from baseline to recovery. Heart rate (HR) and rate pressure product (RPP) were augmented at IP following IRE compared to TRE. HR was significantly elevated for 20 minutes after both RE protocols, and RPP recovered by five minutes. Systolic blood pressure was increased at IP compared to baseline and all recovery time points for both RE protocols. Our research demonstrated that both RE protocols, produced transient increases in platelet indices (MPV, and P_LCR) and hemodynamic variables (SBP, HR, and RPP), all of which returned to baseline within an hour. Notably, the IRE protocol elicited a greater increase in HR and RPP compared to the TRE protocol.

Effects of foam rolling and strength training on post exercise hypotension in normotensive women: A cross-over study.

Foam rolling (FR) has recently become very popular among athletes and recreational exercisers and is often used during warm up prior to strength training (ST) to induce self-myofascial release. The purpose was to examine the acute effects of ST and FR performed in isolation or in combination on blood pressure (BP) responses during recovery in normotensive women. Sixteen normotensive and strength trained women completed four interventions: 1) rest control (CON), 2) ST only, 3) FR only, and 4) ST immediately followed by FR (ST + FR). ST consisted of three sets of bench press, back squat, front pull-down, and leg press exercises at 80% of 10RM. FR was applied unilaterally in two sets of 120 s to each of the quadriceps, hamstring, and calf regions. Systolic (SBP) and diastolic (DBP) BP were measured before (rest) and every 10 min, for 60 min, following (Post 10-60) each intervention. Cohen's d effect sizes were calculated to indicate the magnitude effect by the formula d = Md/Sd, where Md is the mean difference and Sd is the standard deviation of differences. Cohen's d effect-sizes were defined as small (≥0.2), medium (≥0.5), and large (≥0.8). There were significant reductions in SBP for ST at Post-50 (p < 0.001; d = -2.14) and Post-60 (p < 0.001; d = -4.43), for FR at Post-60 (p = 0.020; d = -2.14), and for ST + FR at Post-50 (p = 0.001; d = -2.03) and Post-60 (p < 0.001; d = -2.38). No change in DBP was observed. The current findings suggest that ST and FR performed in isolation can acutely reduce SBP but without an additive effect. Thus, ST and FR can both be used to acutely reduce SBP and, importantly, FR can be added to a ST regimen without furthering the SBP reduction during recovery.

Effects of resistance exercise alone or with caffeine on hemodynamics, autonomic modulation and arterial stiffness in resistance-trained women.

AIM: Both an acute bout of resistance exercise (RE) and caffeine consumption can significantly alter hemodynamics, autonomic modulation, and arterial stiffness, which may correlate with adverse cardiovascular events. However, effects of an acute bout of RE and caffeine are unclear in resistance-trained women. PURPOSE: The purpose of this study was to compare the effects of an acute bout of RE with repetitions to failure on squat and bench press, with or without caffeine, on performance, resting and recovery measures of hemodynamics, autonomic modulation, as well as arterial stiffness in resistance-trained women. METHODS: Eleven women participated in a double-blind, placebo controlled cross-over design in which they consumed caffeine (4 mg/kg) or placebo at least 72 h apart. Sixty minutes following ingestion, participants performed two sets of 10 repetitions followed by a third set to failure on squat and bench press. Hemodynamics, autonomic modulation, and arterial stiffness were measured at rest, 60 min post-ingestion, and three minutes and 10 min following RE. RESULTS: Data demonstrated caffeine has no additive effects on performance, hemodynamics, autonomic modulation, or arterial stiffness (p > 0.05) before or following an acute bout of RE in resistance-trained women compared to a placebo. CONCLUSIONS: Resistance-trained women may not observe any alteration to RE performance on the squat and bench press in terms of repetitions to failure following caffeine ingestion. In addition, the data from the present study suggests that there may also not be any further negative effects on the cardiovasculature if caffeine is consumed prior to the RE bout.

Effects of a Cool-Down after Supramaximal Interval Exercise on Autonomic Modulation.

Supramaximal interval exercise alters measures of autonomic modulation, while a cool-down may speed the recovery of vagal modulation. The purpose of this study was to compare the effects of a cool-down (pedaling a cycle ergometer at 50 rpm against a resistance of 45 W) versus passive recovery (no pedaling) after supramaximal interval exercise on autonomic modulation. Sixteen moderately active individuals (Mean ± SD: 23 ± 3 years (men: n = 10; women: n = 6) were assessed for autonomic modulation at Rest, and 15 (R15), 30 (R30), 45 (R45) and 60 (R60) min following supramaximal interval exercise. Linear measures of autonomic modulation included natural log (ln) total power (lnTP), high-frequency power (lnHF), the ratio of low frequency (LF) to HF ln(LF/HF) ratio, root mean square of successive differences between normal heartbeats (lnRMSSD), while non-linear measures included sample entropy (SampEn) and Lempel-Ziv entropy (LZEn). Two-way repeated ANOVAs were used to evaluate the main effects of condition (cool-down, passive recovery) across time (Rest, and R15, R30, R45 and R60). There were significant (p ≤ 0.05) condition by time interactions for SampEn and LZEn, such that they decreased at 15, 30, 45 and 60 min during passive recovery compared to Rest, with the recovery of SampEn and LZEn by 60 and 45 min, respectively, during cool-down. There were significant (p ≤ 0.05) main effects of time for lnTP, lnHF and lnRMSSD, such that lnTP, lnHF and lnRMSSD were attenuated, and lnLF/HF ratio was augmented, at all recovery times compared to Rest. These data demonstrate that a cool-down increases the recovery of nonlinear measures of vagal modulation within 45-60 min after supramaximal interval exercise, compared to passive recovery in moderately active individuals.

Cardiac Autonomic Function Following Bilateral and Unilateral Upper Body Acute Resistance Exercise.

The purpose of this study was to compare cardiac autonomic responses following bilateral and unilateral upper-body (UB) acute resistance exercise (ARE). In total, 14 individuals were assessed for markers of cardiac autonomic responses via heart rate variability (HRV) and baroreflex sensitivity (BRS) at rest and at 10- and 30-min following ARE. Logarithmically transformed (ln) HRV measures included: total power (ln TP), high-frequency power (ln HF power), low-frequency power (ln LF power), sympathovagal balance (ln LF: HF), and the square root of the mean squared differences of successive R-R intervals (ln RMSSD). BRS was assessed using the sequence method. Two-way repeated measures ANOVAs were used to analyze effects of UB ARE (bilateral, unilateral) across time (Rest, 10, and 30 min). There were no significant (p > 0.05) interactions. However, there were significant (p ≤ 0.05) main effects of time such that ln TP, ln HF power, ln RMSSD, and BRS decreased and did not recover within 30 min compared to Rest for both conditions. Collectively, this study suggests that bilateral and unilateral UB ARE yielded similar reductions, for at least 30 min, in respect to vagal measures of HRV and BRS.

Hemodynamic response and pulse wave analysis after upper- and lower-body resistance exercise with and without blood flow restriction.

Resistance exercise (RE) has been shown to elevate hemodynamics and pulse wave reflection. However, the effects of acute RE with blood flow restriction (BFR) on hemodynamics and pulse wave reflection are unclear. The purpose of this study was to evaluate the differences between upper- and lower-body RE with and without BFR on hemodynamics and pulse wave reflection. Twenty-three young resistance-trained individuals volunteered for the study. Hemodynamics and pulse wave reflection were assessed at rest, 10, 25, 40, and 55 min after either upper- or lower-body with or without BFR. The upper-body RE (URE) consisted of the latissimus dorsi pulldown and chest press; the lower-body RE (LRE) consisted of knee extension and knee flexion. The BFR condition consisted of four sets of 30, 15, 15, and 15 repetitions at 30% 1-repetition maximum (1RM) while the without BFR condition consisted of four sets of 8 repetitions at 70% 1RM. Heart rate, rate pressure product, and subendocardial viability ratio significantly (p < 0.05) increased after all exercises. Brachial and aortic systolic blood pressure (BP) significantly (p < 0.05) elevated after LRE while brachial and aortic diastolic BP significantly (p < 0.05) reduced after URE. Augmentation pressure, augmentation index (AIx), AIx normalized at 75 bpm, and wasted left ventricular pressure energy significantly (p < 0.05) increased after URE while transit time of reflected wave significantly (p < 0.05) decreased after LRE. URE places greater stress on pulse wave reflection while LRE results in greater responses in BP. Regardless of URE or LRE, the cardiovascular responses between BFR and without BFR are similar.HIGHLIGHTS High-load resistance exercise and low-load resistance exercise with blood flow restriction may produce similar cardiovascular responses.Upper-body resistance exercise generates greater changes on pulse wave reflections while lower-body resistance exercise induces greater elevations in systolic blood pressure.

Sex Differences in Measures of Wave Reflection and Aortic Arterial Stiffness in Response to Weight Machine Resistance Exercise.

While it has been demonstrated that acute resistance exercise (RE) alters measures of wave reflection and aortic arterial stiffness in young, healthy individuals, limited research has evaluated sex differences. Accordingly, we recruited moderately active, resistance-trained men (Age: 22 ± 3yrs, n=12) and women (23 ± 3yrs, n=10) to perform two randomized conditions consisting of an acute bout of weight machine RE or a quiet control (CON). Measures of aortic wave reflection and aortic stiffness were taken at baseline and 15 minutes following the RE (Recovery). At baseline, women had significantly higher heart rate (p = 0.05) and lower brachial systolic blood pressure (p = 0.009) compared to men. There were no significant three-way interactions for any variable. Significant condition by time interactions were noted for heart rate (Baseline: 65 ± 10bpm, Recovery: 87 ± 13bpm, p = 0.001), brachial systolic blood pressure (Baseline: 116 ± 9mmHg, Recovery: 123 ± 10mmHg, p = 0.014), and the augmentation index (AIx) normalized at 75bpm (Baseline: 7.7 ± 12.8%, Recovery: 15.5 ± 9.5%, p = 0.002) such that Recovery was augmented compared to Baseline following RE but not CON. There was also a significant main effect of time for augmentation pressure (Baseline: 4.1 ± 4.0mmHg, Recovery: 4.0 ± 3.6mmHg, p = 0.04) such that it decreased from Baseline to Recovery following RE but not the CON. There were no significant effects of sex, condition, or time on aortic arterial stiffness. Men and women have similar responses in measures of aortic wave reflection and aortic arterial stiffness following acute RE using weight machines.

Vascular Responses to High-Intensity Battling Rope Exercise between the Sexes.

The purpose of the study was to assess high-intensity battling rope exercise (HI-BRE) on hemodynamics, pulse wave reflection and arterial stiffness during recovery and between sexes. Twenty-three young, healthy resistance-trained individuals (men: n = 13; women: n = 10) were assessed for all measures at Rest, as well as 10-, 30-, and 60-minutes following HI-BRE. A one-way repeated measures ANOVA was used to analyze the effects of HI-BRE across time (Rest, 10, 30, and 60-minutes) on all dependent variables. Significant main effects were analyzed using paired t-tests with a Sidak correction factor. Significance was accepted a priori at p 0.05. There were significant reductions in hemodynamic measures of diastolic blood pressure (BP) in women, but not men following HI-BRE at 30 minutes. Further, measures of pulse wave reflection, specifically those of the augmentation index (AIx) and wasted left ventricular energy (ΔEw), were significantly increased in both men and women for 60 minutes, but changes were significantly attenuated in women suggesting less ventricular work. There were also significant increases in arterial stiffness in regard to the aorta and common carotid artery that were fully recovered by 30 and 60 minutes, respectively with no differences between men and women. Thus, the primary findings of this study suggest that measures of hemodynamics and pulse wave reflection are collectively altered for at least 60 minutes following HI-BRE, with women having attenuated responses compared to men.

Sex-Specific Autonomic Responses to Acute Resistance Exercise.

Background and Objectives: Acute resistance exercise (RE) reduces vagal modulation and increases sympathovagal balance, which increases the risk for arrythmias. Few studies have examined sex differences in autonomic modulation after acute RE. The purpose of this investigation was to examine sex-specific responses to acute RE on autonomic modulation. Materials and Methods: Twenty-one resistance-trained individuals (men n = 11, women n = 10) between the ages of 19 and 25 y were analyzed for autonomic modulation in response to acute RE and a control (CON). Measures of autonomic modulation were collected at rest, 15 (R15), and 30 (R30) min following both conditions. Heart rate (HR), log transformed root mean square of successive differences (lnRMSSD), total power (lnTP), low-frequency power (lnLF), high-frequency power (lnHF), sample entropy (SampEn), and Lempel-Ziv entropy (LZEn) were measured at all time points. A three-way repeated analysis of variance (ANOVA) was used to analyze sex (men, women) across condition (RE, CON) and time (Rest, R15, R30). Results: The results are similar for all heart rate variability (HRV) variables at rest for both conditions (RE, CON). SampEn was significantly higher in men compared to women at rest for both conditions (p = 0.03), with no differences in LZEn (p > 0.05). There were no significant (p > 0.05) three-way interactions on any variables. Condition by time interactions demonstrated that both sexes increase in HR (p = 0.0001) and lnLF/HF ratio (p = 0.001), but decreases in lnRMSSD (p = 0.0001), lnTP (p < 0.0001), lnLF (p < 0.0001), lnHF (p = 0.0001), and LZEn (p = 0.009) at R15 and R30 compared to rest following acute RE and were different from CON. Condition by time interaction (p = 0.017) demonstrated that SampEn was attenuated at R15 compared to rest, and the CON, but not R30 following acute RE. Conclusion: Although SampEn is more complex at rest in men compared to women, autonomic modulation responses between sexes following acute RE appear to be similar.

Set Configuration in Strength Training Programs Modulates the Cross Education Phenomenon.

ABSTRACT: Fariñas, J, Mayo, X, Giraldez-García, MA, Carballeira, E, Fernandez-Del-Olmo, M, Rial-Vazquez, J, Kingsley, JD, and Iglesias-Soler, E. Set configuration in strength training programs modulates the cross education phenomenon. J Strength Cond Res 35(9): 2414-2420, 2021-This study aimed to compare the strength gains in the nontrained arm after 2 independent unilateral training programs differing in the set configuration. Thirty-five subjects were randomly assigned to 3 groups: traditional training (TT; n = 12), cluster training (CT; n = 11), or control (CON; n = 12). The experimental groups performed a 5-week training program of a unilateral biceps curl exercise with the dominant limb using the 10 repetition maximum (10RM) load. Traditional training performed 5 sets of 6 repetitions and 135 seconds of rest between sets. Cluster training completed 30 repetitions with 18.5 seconds of rest between each repetition. Anthropometry (ANT), muscle thickness (MT), 1RM, the number of repetitions with 10RM (n10RM), and isometric maximal voluntary contraction (MVC) were measured before and after the intervention. Regarding the nontrained arm, TT improved 1RM (7.3%, p < 0.001). No changes were observed in CT. Regarding the trained arm, TT improved 1RM (9.1%, p < 0.001), n10RM (p = 0.005), and MVC (p = 0.011), whereas CT only showed a trend for improvement of 1RM (3.4%, p = 0.052). These results suggest that when total volume and repetition-to-rest ratio are equated, a more fatiguing set configuration causes a higher effect on the non-trained limb.

The Effects of Machine-Weight and Free-Weight Resistance Exercise on Hemodynamics and Vascular Function.

The purpose of this study was to examine hemodynamic and vascular responses between machine-weight and free-weight exercise. Resistance-trained individuals were assigned to a machine-weight (n = 13) or free-weight (n = 15) group. Groups completed two visits consisting of their assigned exercise condition and a control (CON). A 2 × 2 × 3 repeated measures ANOVA was used to test the effects of group across condition and time on the hemodynamic parameters [cardiac output (CO), heart rate (HR), total peripheral resistance (TPR), mean arterial pressure (MAP), and stroke volume (SV)]. A 2 × 2 × 2 repeated measures ANOVA was used to test the effects of group across condition and time on the hemodynamic variable, forearm vascular conductance (FVC), as well as on vascular measures [forearm blood flow (FBF), blood flow peak, and total reactive hyperemia (RH)]. Main effects were analyzed using pairwise comparisons. The results of the present study demonstrate that both machine-weight and free-weight exercise produce similar (p > 0.05) alterations in hemodynamics and vascular function. Specifically, during recovery both groups demonstrated significant (p ≤ 0.05) increases in measures of hemodynamics such as CO, HR and FVC, as well as significant (p ≤ 0.05) decreases in TPR, MAP, and SV. Measures of vascular function such as FBF, blood flow peak, and total RH were also significantly (p ≤ 0.05) increased during recovery. Therefore, this study suggests that either machine weight or free-weight exercise may induce acute hemodynamic and vascular benefits, which may reduce the risk of cardiovascular disease (CVD) and CVD events.

A short set configuration attenuates the cardiac parasympathetic withdrawal after a whole-body resistance training session.

PURPOSE: We aimed to analyse the acute effects of set configuration on cardiac parasympathetic modulation and blood pressure (BP) after a whole-body resistance training (RT) session. METHODS: Thirty-two participants (23 men and 9 women) performed one control (CON) and two RT sessions differing in the set configuration but with the same intensity (15RM load), volume (200 repetitions) and total resting time (360 s between sets for each exercise and 3 min between exercises): a long set configuration (LSC: 4 sets of 10 repetitions with 2 resting minutes) and a short set configuration session (SSC, 8 sets of 5 repetitions with 51 resting seconds). Heart rate variability, baroreflex sensitivity, the low frequency of systolic blood pressure oscillations (LFSBP), BP and lactatemia were evaluated before and after the sessions and mechanical performance was evaluated during exercise. RESULTS: LSC induced greater reductions on cardiac parasympathetic modulation versus SSC after the session and the CON (p < 0.001 to p = 0.024). However, no LFSBP and BP significant changes were observed. Furthermore, LSC caused a higher lactate production (p < 0.001) and velocity loss (p ≤ 0.001) in comparison with SSC. CONCLUSION: These findings suggest that SSC attenuates the reduction of cardiac parasympathetic modulation after a whole-body RT, improving the mechanical performance and decreasing the glycolytic involvement, without alterations regarding vascular tone and BP.

Radiofrequency Ablation for the Treatment of Painful Neuroma.

Mechanical compression of interdigital nerves beneath the deep transverse intermetatarsal ligament and between the metatarsal heads leads to painful irritation and possible fibrosis. Conservative measures of padding and injections often fail to provide long-term relief. Surgical excision provides definitive relief, but the procedure is not without risk. Incomplete excision and stump neuroma formation are a few of the possible complications associate with open excision. This retrospective cohort study was performed to provide a review of the available literature on the identification and treatment of interdigital neuromas and to examine the overall incidence of patient satisfaction after radiofrequency ablation as definitive treatment for interdigital neuroma formation. This study population consisted of 32 patients (25 females and 7 males with 1 patient having bilateral procedures) with a mean age of 46.3 ± 17 (range 31 to 65) years. For all procedures, the median patient satisfaction score was 92.5 (interquartile range 50 to 100) of 100, with a mean follow-up period of > 2.5 years. Only 1 patient in the study population reported no relief after 3 total procedures. Radiofrequency ablation offers a minimally invasive alternative with a short postoperative recovery course and considerably fewer complications compared with surgical excision of the intermetatarsal neuroma as described in prior reports.

Free-weight versus weight machine resistance exercise on pulse wave reflection and aortic stiffness in resistance-trained individuals.

The purpose of this study was to compare the vascular responses to acute free-weight (FW) resistance exercise (RE) versus weight machines (WM). Thirty-two resistance-trained individuals participated in this study. Both modalities involved performing acute RE and a control. Blood pressure and measures of pulse wave reflection were assessed using pulse wave analysis. Aortic stiffness was assessed using carotid-femoral pulse wave velocity (cf-PWV). A repeated measures analysis of variance was used to determine the effects of modality (FW and WM) and condition (acute RE and control) across time (rest and 10-20 min after exercise) on measures of pulse wave reflection and aortic stiffness. Significance was set a priori at p ≤ 0.05. There were no modality by condition by time interactions for any variable, such that the FW and WM modalities responded similarly across time after acute RE (p > 0.05). There were significant (p ≤ 0.05) increases in heart rate, aortic systolic blood pressure, aortic pulse pressure, augmentation index normalized at 75bpm, and decreases in subendocardial viability ratio (SEVR) after acute RE, compared to rest. There was also a significant (p ≤ 0.05) increase in cf-PWV after acute RE, compared to rest. In conclusion, this study demonstrates that acute free-weight and weight-machine RE are associated with transient increases in measures of pulse wave reflection and aortic stiffness, with reductions in myocardial perfusion. These data demonstrate that both modalities result in significant stress on the myocardium during recovery, while simultaneously increasing pressure on the aorta for at least 10-20 min.

Autonomic modulation following an acute bout of bench press with and without blood flow restriction.

PURPOSE: Traditional resistance exercise decreases vagal tone up to 30 min after an acute bout of resistance exercise, which may increase the risk of cardiovascular events. However, the effects of resistance exercise with blood flow restriction (BFR) on autonomic modulation are unclear. To evaluate autonomic modulation after resistance exercise with and without BFR in resistance-trained men. METHODS: Eleven young men volunteered for the study. Autonomic modulation was assessed at rest, 15 (Rec 1), and 25 (Rec 2) minutes after low-load bench press with BFR (LL-BFR), traditional high-load bench press (HL), and a control (CON). Autonomic modulation assessments were expressed as natural logarithm (Ln), and included total power (LnTP), low-frequency power (LnLF), high-frequency power (LnHF), sympathovagal balance (LnLF/LnHF ratio), root mean square of the successive differences (LnRMSSD), and the proportion of intervals differing by > 50 ms from the preceding intervals (LnPNN50). A repeated measures ANOVA was used to evaluate conditions (LL-BFR, HL and CON) across time (Rest, Rec1, and Rec2) on autonomic modulation. RESULTS: There were significant condition by time interactions for LnTP, LnHF, and LnRMSSD such that they were reduced during recovery after LL-BFR and HL compared to Rest and CON. There were no interactions in the LnLF, LnLF/LnHF ratio, and LnPNN50. CONCLUSIONS: These data suggest that LL-BFR and HL significantly alter autonomic modulation up to 30 min after exercise with significant reduction after HL compared to LL-BFR when exercise volume is equated.

Perceived Exertion Is Affected by the Submaximal Set Configuration Used in Resistance Exercise.

Mayo, X, Iglesias-Soler, E, and Kingsley, JD. Perceived exertion is affected by the submaximal set configuration used in resistance exercise. J Strength Cond Res 33(2): 426-432, 2019-Previously, perceived exertion in submaximal resistance exercise protocols was reported to be affected by the intensity of load followed by work-to-rest ratio. Nevertheless, the effect of set configuration, which entails the metabolic, hormonal, and neuromuscular implication of the session, is currently unknown, despite the fact that perceived exertion discriminates these differences. We aimed to analyze the effect of 3 submaximal set configurations on perceived exertion and their relationship with velocity as a mechanical measure of fatigue. Seventeen healthy subjects (23 ± 2 years) performed with the 10-repetition maximum load on the leg press (211 ± 45 kg) a total of 40 repetitions with 720 seconds of rest in 3 randomized experimental sessions with the same work-to-rest ratio. The sessions consisted of an interrepetition rest design performing individual repetitions, a cluster design performing groups of 4 repetitions, and a traditional design performing groups of 8 repetitions. At the end of the session, the nonparametric analysis of variance-type test revealed differences between protocols (p < 0.001), with lower values of perceived exertion in the interrepetition rest design in comparison with the cluster design (p = 0.003) and traditional design (p < 0.001). In addition, Spearman's rank correlations (p < 0.001) were observed for the interrepetition rest design (rho = -0.72) and traditional design (rho = -0.8) between perceived exertion and velocity. Our findings suggest that the submaximal set configuration is a determinant of perceived exertion by itself, and that perceived exertion represents similar mechanisms as velocity, such as fatigue and certain characteristics of the session and the individual.

Autonomic modulation and baroreflex sensitivity after acute resistance exercise: responses between sexes.

BACKGROUND: The aim of this study was to evaluate autonomic modulation, blood pressure variability and baroreflex sensitivity (BRS) responses to an acute bout of free-weight resistance exercise in resistance-trained men (N.=14) and women (N.=13). METHODS: Participants underwent both an acute bout of resistance exercise (RE) consisting of 3 sets of 10 repetitions at 75% 1-repetition maximum on the squat, bench press, and deadlift, and a quiet control. Autonomic modulation, blood pressure variability (LFSAP), and cardiovagal BRS were assessed at rest, 15-20 minutes (Rec1) and 25-30 minutes (Rec2) postexercise. Log transformed measures of autonomic modulation included root square of the mean ssquared differences of successive RR intervals (LnRMSSD), high-frequency power (LnHFRR) and low-frequency power (LnLFRR) and sympathovagal balance (LnLFRR/HFRR). LFSAP was used as a measurement of vasomotor tone. Cardiovagal BRS was assessed using the sequence method. RESULTS: There were no significant sex differences at rest and no significant sex by time by condition interactions for any variable. Compared with rest there were augmentations in LnLFRR/HFRR (P=0.002) and LFSAP (P=0.001) at Rec1 and Rec2. RMSSD and cardiovagal BRS were significantly (P=0.0001) decreased at Rec1 and Rec2 compared to rest after the acute RE. CONCLUSIONS: Both sexes demonstrated that acute resistance exercise using free weights has a profound impact on autonomic modulation, blood pressure variability and cardiovagal BRS.

Pulse wave reflection responses to bench press with and without practical blood flow restriction.

Resistance exercise is recommended to increase muscular strength but may also increase pulse wave reflection. The effect of resistance exercise combined with practical blood flow restriction (pBFR) on pulse wave reflection is unknown. The purpose of this study was to evaluate the differences in pulse wave reflection characteristics between bench press with pBFR and traditional high-load bench press in resistance-trained men. Sixteen resistance-trained men participated in the study. Pulse wave reflection characteristics were assessed before and after low-load bench press with pBFR (LL-pBFR), traditional high-load bench press (HL), and a control (CON). A repeated-measures ANOVA was used to evaluate differences in pulse wave reflection characteristics among the conditions across time. There were significant (p ≤ 0.05) interactions for heart rate, augmentation index, augmentation index normalized at 75 bpm, augmentation pressure, time-tension index, and wasted left ventricular energy such that they were increased after LL-pBFR and HL compared with rest and CON, with no differences between LL-pBFR and HL. Aortic pulse pressure (p < 0.001) was elevated only after LL-pBFR compared with rest. In addition, there was a significant (p ≤ 0.05) interaction for aortic diastolic blood pressure (BP) such that it was decreased after LL-pBFR compared with rest and CON but not HL. The subendocardial viability ratio and diastolic pressure-time index were significantly different between LL-pBFR and HL compared with rest and CON. There were no significant interactions for brachial systolic or diastolic BP, aortic systolic BP, or time of the reflected wave. In conclusion, acute bench press resistance exercise significantly altered pulse wave reflection characteristics without differences between LL-pBFR and HL.